Container seal closure and assembly

ABSTRACT

A seal closure for a container includes a closure body and a plug liner. In embodiments, the closure body includes an upper wall, an outer annular wall, a radially outer support portion, and a radially inner support portion. The outer annular wall includes formations configured to engage a neck portion of a container. The plug liner may be configured to extend radially across the radially inner support portion. A hollow space can be formed by and provided between the plug liner, the radially inner support portion, and the upper wall. Embodiments of the closure may also include a plug seal. A method for designing or configuring a closure to accommodate or displace a headspace associated with a container is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/595,882, filed Feb. 7, 2012, which is incorporated by reference as though fully set forth herein.

TECHNICAL FIELD

This invention relates generally to closures for containers, including closures and closure assemblies suitable for use in connection with hot-fill applications.

BACKGROUND

Plug-type closures can fill in headspace associated with containers. Headspace generally comprises an area provided between the fill level of the product contents and the associated cap. In applications, a secondary vacuum can build up with an absorption of remaining headspace by product contents. The fill level can rise as a result of the associated vacuum, but will generally stabilize when the level comes into contact with the plug. With traditional closure systems the structure of the bottle may be configured to resist the vacuum associated with nearly all of the headspace.

Plug seal closures can provide a useful option to reduce gram weight by employing a thinner neck (or “E-wall”). However, with a thinner E-wall, a conventional container can be more prone to ovalization or warping, particularly with hot-fill applications. It is desirable to provide a container closure and assembly that can serve a dual purpose of providing a sealing function and protecting the neck (e.g., serving as a form of insulator). It can further be desirable to provide closures that, inter alia, may provide:

(a) a lower fill level at opening for consumer convenience than traditional fill level specifications used to minimize headspace;

(b) less/smaller oxygen (O²) headspace content (which can provide better product quality);

(c) improved resistance to bottle-to-bottle contact pressure when product contents reach an associated plug;

(d) improved resistance to denting and ovalization under secondary vacuum when product contents reach an associated plug; and/or

(e) opportunities for potential light-weighting.

SUMMARY

With embodiments a closure assembly includes a closure with a plug insert that inserts itself into the headspace of a container and displaces it, which can thereby move an associated fill level closer to the cap. Having the fill level closer to the cap can generate more internal pressure and greater container stability.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, wherein:

FIG. 1 generally illustrates a side partial cross-sectional view of an embodiment of a container closure;

FIG. 2 generally illustrates a side partial cross-sectional view of an embodiment of a container closure including a plastic plug liner extending from a radially inner support portion;

FIG. 3 generally illustrates a side view of an embodiment of a preform;

FIG. 4 illustrates a cross-sectional side view of the preform shown in FIG. 3, viewed along section line B-B;

FIG. 5 illustrates a top view of the preform shown in FIG. 3, including thread vents;

FIG. 6 illustrates an enlarged view of a portion of the preform shown in FIG. 5, which generally illustrates a thread vent;

FIG. 7 generally illustrates a side view of a container seal closure according to an embodiment of the present disclosure;

FIG. 8 illustrates a cross-sectional view of the closure shown in FIG. 7, viewed along section line A-A;

FIG. 9 illustrates a detail view of a portion of the closure shown in FIG. 8;

FIG. 10 generally illustrates a perspective cross-sectional view of an embodiment of a container closure, shown without the inclusion of a plastic plug liner; and

FIG. 11 generally illustrates a variation in product fill levels at different stages.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of the present invention, examples of which are described herein and illustrated in the accompanying drawings. While the invention will be described in conjunction with embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention.

FIG. 1 generally illustrates a side partial cross-sectional view of an embodiment of a container closure 10. The illustrated closure 10 has a closure body 20 that includes an upper wall 30, an outer annular wall 40, a radially outer support portion 50, and a radially inner support portion 60. The outer annular wall 40 can include formations (e.g., thread receiving formations 70), which can be configured to engage a neck portion of a container. The closure body 20 may, for example, comprise a polymer, such as polyethylene (PE), polypropylene (PP), or the like.

FIG. 2 generally illustrates a side partial cross-sectional view of an embodiment of a container closure 10 similar to that shown in FIG. 1, and including an embodiment of a plug liner 80. If desired, the plug liner 80 may be formed as a unitary extension of the radially inward support portion 60. That is, with general reference FIG. 2, the radially inward support portion 60 may, for instance, comprise a similar portion as that illustrated in FIG. 1 (e.g., that up to the imaginary line included between portion 60 and liner 80), with the plug liner 80 continuing to extend downward therefrom. In other embodiments, portion 60 and liner 80 may be connected discrete components. In the embodiment generally illustrated in FIG. 2, the plug liner 80 extends downward from and radially across the radially inner support portion 60. Also, as generally illustrated in FIG. 2, for embodiments, at least a portion of the plug liner 80, and perhaps all or a significant portion of the plug liner 80, may have a wall thickness that is the same or greater than the wall thickness of the radially inward support portion 60.

It is noted that the plug liner 80 may extend vertically below the lowermost vertical point of the radially inward support portion 60 (e.g., as illustrated in FIG. 2, in which the vertical distance below the inner support portion 60 is nearly the same vertical distance as the inner support portion extends below the upper wall 30) or, if desired, may extend radially across at or about the same vertical lowermost portion of the radially inward support portion 60 (e.g., as illustrated in FIGS. 8 and 9, which may be nearly flush). The plug liner 80 may be a fixed and rigid plug, i.e., that substantially resists flex-inducing forces. With embodiments, the plug liner 80 can be configured/adjusted to increase or decrease its lowermost vertical position, which in turn can take up a desirable amount of anticipated headspace. For embodiments, a plug liner 80 may be configured such that a fill level will be as close to the plug liner 80 as possible without encountering an undesirable impact.

As generally illustrated, a hollow space 90 may be formed by and provided between the plug liner 80, the radially inner support portion 60, and the upper wall 30. Additionally, as generally shown, the inclusion of the plug liner 80 will serve to displace headspace (typically atmosphere or air residing above the container contents) in connection with a closed/sealed container. The closure 10 may be produced by various methods known in the art, including injection molding, co-injection molding, and/or compression molding.

By configuring and/or adjusting the plug liner 80 and hollow space 90, the closure can be configured to accommodate or displace a headspace associated with a container. Digital models (e.g., computer or CAD models of the components) may be generated and adapted to provide a design for a closure with plug liner and/or a hollow space to address desired container fill levels or other objectives. In embodiments, a digital model for a seal closure having an upper wall, an outer annular wall, a radially outer support portion, and a radially inner support portion can be created or generated. A digital representation of a plug liner and hollow space may be included with the digital model of the closure. Various elements of the digital model can be adjusted or configured to meet desired objectives. For example and without limitation, (i) the volume of the hollow space, (ii) the size and/or the shape of the plug liner, or both (i) and (ii) may be adjusted or configured to meet an anticipated container fill condition. Aspects of the aforementioned process can be used to provide a closure for a container that minimizes an associated headspace. With brief reference to FIG. 11, by way of example and without limitation, such a method may be utilized to configure a closure to minimize an associated headspace at an appropriate time relative to filling, such as to minimize a difference between fill levels PFL₁ and PFL₂. FIGS. 3, 4, 5, and 6 generally illustrate an embodiment of a preform 100 and portions thereof, including a neck portion 110. The illustrated neck portion 110 includes a support flange 120 and external threads 130. Such a preform 100 will commonly be molded, e.g., blow molded, to form a resultant container. The preform 100 (and consequently the resulting plastic container) may comprise a plastic, and can, for example, be obtained from injection molding, injection stretch blow molding, extrusion blow molding, and/or compression molding. In embodiments, the preform 100 may be comprised of plastic in either a monolayer or multilayer configuration. In a monolayer configuration, the preform 100 may be comprised of polyethylene (PE), polyethylene terephthalate (PET), high-density polyethylene (HDPE), polypropylene (PP), and other known polymers known in the container art. In a multilayer configuration, preform 100 may include two or more layers of polymers that are provided over all or portions of the container. It is noted that for many embodiments that employ molding techniques known in the art, the dimensions of the neck portion for the molded container will remain substantially consistent with the dimensions of the neck portion of the preform.

FIG. 5 generally illustrates a top plan view of an embodiment of a preform 100, which may be of the type generally shown in FIG. 3. The preform may have a parting line PL, such as depicted, and may include one or more thread vents 132, such as generally illustrated in FIGS. 5 and 6. As illustrated in FIG. 6, the thread vents 132 may have a centerline positioned at an angle Θ (shown illustrated from a 6 o'clock position). Without limitation, in embodiments angle Θ may be about 45°.

FIG. 7 generally illustrates a side view of a container seal closure 10 according to an embodiment of the present disclosure. A cross-sectional view of the closure 10 is shown in FIG. 8. As perhaps better illustrated in the enlarged detail view (E) of FIG. 9, or the perspective view of FIG. 10, the seal closure may include a plug seal 140 provided at or adjacent the upper wall 30, and radially between the radially outer support portion 50 and the radially inner support portion 60. The radially outer support 50 and the radially inner support 60 can provide support to a neck finish including, for example and without limitation, thin-wall hot-fill neck finishes. As generally illustrated, the radially inner support portion 60 may include a lower curved portion 62 that, among other things, can provide a surface to facilitate the insertion of a container neck portion 110′. By way of example, for some embodiments of closure assemblies (which includes a container and closure), the thin-wall hot-fill neck finish may have a thickness of 0.047 inches, or less. The plug seal 140 can, among other things, provide additional top seal integrity. In embodiments, the plug seal 140 can, without limitation, be comprised of a thermoplastic elastomer (TPE) (sometimes referred to as thermoplastic rubber) and/or an ethylene vinyl acetate (EVA) material.

As generally illustrated in FIGS. 9 and 10, a measure of space can exist or occur along all or a portion of the vertical zone of potential contact between the container neck portion 110′ and the radially inner support 60. Both FIGS. 9 and 10 show the inclusion of a plug seal 140, and FIG. 10 illustrates an embodiment in which there is a segment having significant sealing contact between the container neck portion 110′ and the radially inner support 60.

FIG. 11 generally illustrates a variation in product fill levels in connection with a container neck portion 110′ and closure 10 at different stages. PFL₁ generally represents a product fill level after filling and capping and prior to vacuum absorption (which may be provided by the container's vacuum panels) product cooling in a traditional “panel” bottle. PFL₂ generally represents a product fill level associated with an instant embodiment after the associated headspace has disappeared or dissipated. With embodiments, an objective may be to minimize the differential between fill levels PFL₁ and PFL₂.

It is noted that the foregoing concepts may be used in connection with various other hot-fill related container system techniques that address internal pressures and/or vacuum forces, including post-sealing techniques. For example, closures such as described herein may be used in connection with techniques for heating and/or pressurizing plastic containers disclosed in U.S. patent application Ser. No. 12/702,370, filed Feb. 9, 2010, and U.S. Pat. No. 7,735,300, published Jun. 15, 2010, which are incorporated herein in their entirety by reference. For instance, heating, pressurizing and/or other hot-fill related techniques can be additionally employed to provide further vacuum absorption post-sealing, while the inclusion of a plug liner can serve to reduce the associated headspace to be offset. While some post-sealing processes can increase the internal pressure by displacing headspace, by employing closures with features as described herein, less headspace may need to be addressed.

For example, and without limitation, in an embodiment of a system, a container may be hot-filled with contents and a closure with sealing features (such as disclosed herein) may be applied to seal the container. Then, a post-sealing process for dealing with vacuum absorption (e.g., heating/pressurizing) may be applied to the sealed container. For some embodiments, the maximum distance between the fill level after post-sealing treatment (e.g., heating/pressurizing) and the plug is kept to about 2 mm±1.5 mm.

Although numerous embodiments of this invention have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims. 

What is claimed:
 1. A seal closure for a container, the closure comprising: a closure body including an upper wall, an outer annular wall, a radially outer support portion, and a radially inner support portion; the outer annular wall including formations configured to engage a neck portion of a container; and a plug liner, the plastic plug liner extending radially across the radially inner support portion; wherein a hollow space is formed by and provided between the plug liner, the radially inner support portion, and the upper wall.
 2. The seal closure of claim 1, wherein the radially inner support portion and the plug liner are formed as a unitary component.
 3. The seal closure of claim 1, wherein the plug liner extends vertically downward below the radially inner support portion.
 4. The seal closure of claim 3, wherein the plug liner extends vertically downward a distance that is about the same or greater than a distance that the lowermost point of the radially inner support portion extends vertically downward from the upper wall.
 5. The seal closure of claim 1, wherein the plug liner is substantially fixed and rigid.
 6. The seal closure of claim 5, wherein the plug liner is configured to substantially resist flex-inducing forces.
 7. The seal closure of claim 1, wherein the plug liner has a wall thickness that is at least as thick as a wall thickness of the radially inner support portion.
 8. The seal closure of claim 1, wherein the plug liner is comprised of plastic.
 9. The seal closure of claim 1, including a plug seal provided at or adjacent the upper wall and radially between the radially outer support portion and the radially inner support portion.
 10. The seal closure of claim 1, wherein the plug seal is comprised of plastic.
 11. The seal closure of claim 10, wherein the plug seal is comprised of thermoplastic elastomer or ethylene vinyl acetate.
 12. A method for designing or configuring a closure to accommodate or displace a headspace associated with a container, the method comprising: creating or generating a digital model of a seal closure with a closure body including an upper wall, an outer annular wall, a radially outer support portion, and a radially inner support portion; and creating or generating a plug liner in or with the digital model such that the plug liner extends radially across the radially inner support portion to form a hollow space between the plug liner, the radially inner support portion, and the upper wall.
 13. The method of claim 12, including adjusting the volume of the hollow space.
 14. The method of claim 13, wherein the volume of the hollow space is sized or configured with respect to an anticipated container fill level.
 15. The method of claim 12, including adjusting the size or shape of the plug liner with respect to an anticipated container fill level.
 16. The method of claim 13, including a digital representation of a plug seal with the digital model, the plug seal provided at or adjacent the upper wall and radially between the radially outer support portion and the radially inner support portion.
 17. The method of claim 12, including physically forming or manufacturing a closure with a plug liner and hollow space in accordance with the digital model.
 18. The method of claim 16, including physically forming or manufacturing a closure with a plug liner, hollow space, and plug seal in accordance with the digital model. 